An incandescent halogen lamp of such kind is disclosed in, for example, WO 96/05610 A1. That publication of an unexamined application describes an incandescent halogen lamp for vehicle headlights having a lamp base which defines a reference plane for orienting the incandescent halogen lamp in the vehicle headlight and includes a cylindrical holder part in which a lamp vessel is fixed into position. The lamp vessel of the incandescent halogen lamp has a rotationally symmetrical vessel section that encloses filaments and a dipping cap and which is closed at one end by a lamp-vessel dome and at the other by a lamp-vessel seal. The lamp-vessel seal is fixed into position in the holder part and has electrical supply leads projecting from it for the filaments.
Regulation 37 of the ECE standard specifies a maximum lamp outline for category H7, H8, and H16 incandescent halogen lamps. In particular the lamp's extent L1 in the longitudinal direction from the lamp base's reference plane oriented perpendicularly thereto as far as the lamp-vessel dome must not exceed 44.0 mm. That means the condition L1<44.0 mm must have been met. According to ECE regulation 37 a metal-free zone must furthermore have been ensured in the case of category H7, H8, and H16 incandescent halogen lamps to prevent any disturbance due to scattered light and mirror images in the vehicle headlight. Said metal-free zone is defined schematically in FIG. 4 by straight line G and winding axis A of the coiled filament. Straight line G intersects axis A of the coiled filament 3.0 mm below the first coil of coiled filament 3 at an angle of 40 degrees or, as the case may be, 140 degrees. Angle α between straight line G and horizontal line F extending perpendicularly to coiled-filament axis A (FIG. 4) is hence 50 degrees. According to regulation 37 of the ECE standard, in the case of category H7, H8, and H16 incandescent halogen lamps, except for filament coils there must not be any metal parts in the region inside lamp vessel 1 situated above straight line G and to the right of coiled-filament axis A when the lamp is oriented as selected in FIG. 4. For the aforementioned categories of incandescent halogen lamps it is furthermore specified by regulation 37 of the ECE standard that distance E between the coiled filament and reference plane R defined by the lamp base be in the range of 25.0 mm±0.1 mm. The value for the lamp base's height B above reference plane R is in the 9-to-1′-mm range in the case of incandescent halogen lamps according to the prior art.